France's far-right National Front party has dealt a big blow to the ruling Socialists, with several of its candidates taking prime position in the first round of municipal elections.

The main centre-right opposition UMP party also hailed a "big victory" as initial estimates showed it won in Sunday's elections, as President Francois Hollande suffers record unpopularity against a backdrop of near-zero growth and high unemployment.

According to preliminary results from the interior ministry, the UMP and allies took 47 per cent of the vote nationwide while the Socialist party and allies took 38 per cent, and the National Front (FN) 5 per cent, far higher than its 0.9 per cent vote share in the first round of 2008 polls.

Applauding what she said was "an exceptional vintage for the FN", Marine Le Pen, head of the anti-immigration and anti-EU party, said the polls marked the "end of the bipolarisation of the political scene".

Although the FN had been expected to do well, its first-round results were far better than expected. Far-right candidates were ahead in several key towns and cities that will put them in pole position in the second round on March 30.

In the former coal-mining town of Henin-Beaumont in northern France, Steeve Briois achieved 50.3 per cent, an absolute majority which made him the outright winner and mayor.

Under municipal election rules in France, any candidate who gets more than 50 per cent is declared the winner and there is no need for a second round.

The FN hopes to claim the mayoral role of 10 to 15 mid-sized town after the second round, and if it achieves that, it will have beaten its previous record in 1997 when it had four mayors.

The Socialists immediately responded to the surge of the FN by acknowledging that some voters had registered their discontent with government policies.

"Some voters expressed their concerns, and even their doubts, by abstaining or through their vote," Prime Minister Jean-Marc Ayrault said.

Turnout was dismally low at just 38 per cent, a record low for French municipal elections.

Ayrault called on voters to rally in the second round to block the "advance of the FN", in a mirror of 2002 presidential elections when then FN leader Jean-Marie Le Pen reached the second round, prompting the Socialist Party to urge support for centre-right candidate Jacques Chirac.

"Where the National Front is in a situation where it could win the second round, all democratic and republican forces have the responsibility to create the conditions to stop it from doing so," he said.

This article appeared in the South China Morning Post print edition as Far-right National Front makes gains in polls